9mos old common boa

[Saml8]

Hi everyone, we got a 9mos old common boa at the reptile show two days ago. He's not our first snake but he is our first boa. I know you're not supposed to handle him for awhile but since we brought him home he has been in his hide the whole time. I'm a little concerned about him and hope he's at least come out to drink water. He currently is in a 10 gallon while he's being quarantined with a UTH (on a thermostat) and a ceramic heat lamp (also on a thermostat) his temperatures are around 80 on the cool side and close to 90 on the hot side. We live in Colorado and our house drops down to around 67 and 68 at night. So I've put the ceramic heat bulb on the other side of the tank trying to keep the ambient temperatures close to 80.
One problem I know I have is the humidity is around 30%. We're very dry here in Colorado. As of now I have him on paper towel just so I can observe for mites and his first poop which hasn't happened yet. There's a large water bowl in there but it's not making much of a difference.
My questions are
- any suggestions on keeping my humidity up? Should I just sprayed the enclosure throughout the day?
-how long should I wait before handling him
-how long should I wait before trying to feed him his first meal
-are my temperatures too warm for him?

Thank you so much for taking the time